The present invention relates to a device which is mountable on a printed circuit card and which can be manually operated to aid in inserting a printed circuit card into a receptacle and locking the card in place, and to aid in extracting the card from the receptacle.
It is common practice to provide circuitry for electronic equipment, such as personal computers, on printed circuit cards, or boards, which cards have electrical connectors along one edge and are inserted into receptacles provided in the equipment so that the connectors disposed along one edge of the card mate with connectors permanently installed in the equipment.
It is essential that the card be inserted in a receptacle so as to reach an accurately defined end, or fully inserted, position, in order to assure that a reliable electrical contact is established between all connectors, or terminals, on the card and those permanently installed in the equipment. This generally requires the application of a certain level of force to the card.
Further, if a card must be removed for any reason, a certain extraction force is required and it may prove difficult to manually grip the card in a manner to achieve such extraction force, particularly when a small spacing exists between the card to be extracted and adjacent cards or other equipment components.
Devices which can be attached to a printed circuit card in order to assist in the insertion and removal operations are already on the market. One such device is marketed by the Calmark Corporation of San Gabriel, Calif., under the designation Series 107-20 Card Inserter-Extractor. Two such devices are typically mounted at opposite corners at the edge of a card which is remote from the electrical connectors. Each device cooperates with a support member fixed to the equipment in such a manner that when the device is moved to a locking position, the card is urged into its fully seated position and is locked in that position, while if the device is moved to an extraction position, the card is urged out of engagement with the connectors permanently installed in the equipment, after which the card can easily be withdrawn. The device allows a card to be reliably seated in its fully inserted position and to be easily removed without requiring the user to grip the card itself.
These known devices include a molded detent structure which engages a pin secured to the card in order to hold the device in its locking position and a certain force must be applied to the device to overcome the detent holding force when it is desired to effect card extraction. While this arrangement provides a good locking effect, the detent connection can be inadvertently released, which would result in movement of the device out of its locking position. If this should occur, the card may be caused to move away from its fully inserted position, for example as a result of vibrations occurring within the equipment or accidental contact with the card, with the result that contact between some or all of the connectors on the card and those permanently installed in the equipment can be broken.